Sound reproducing apparatus



Aug. 10, 1937. F. R. MARION 2,089,391

SOUND REPRODUCING APPARATUS Filed June 12, 1956 2 sheets-sneak l'Nl/VTOR By .E RMAR/ON ATTORNEY Filed June 12, 1936 F. R. MARION SOUNDREPRODUCING APPARATUS 2 Sheets-Sheet 2 /Nl/EN7'OR y E R. MAR/0N mmwwATTORNEY Patented Aug. 10, I 1937 Frederick R. Marion, Floral Park, N.Y.. assignor .to Electrical Research Products, Inc., New York. N. Y., acorporation of Delaware Application June 12, 1936, Serial No. 84,841

12 Claims. (cum-2'1)- This invention relates to sound reproducingapparatus and more particularly. to acoustictransducers capable ofdistributing sound over a large space angle and adapted to have a plu-'rality of acdustic devices coupled thereto.

One object of this invention is to distribute sound faithfullyand withsubstantially uniform intensity throughout alarge space angle.

Another object of this invention is to insure substantially uniformsounddistribution throughout a desired space angle from a plurality of hornsdelivering'sound from a plurality of receivers, in the 'event offailureof one of the receivers.-

, In one illustrative embodiment of this invention, a loud-speakercomprises a transducer ineluding a plurality of groups of elongatedflaring horns, horns of one group being interleaved with those ofanother. The horns are arranged sidev by side and in a number of equalrows, and are coupled to a pair of receivers 1' or supplying soundenergy.- Preferably the.horns have their outlets or mouths disposed in aplane.

In accordance with one feature of this inven- 5 tion the inlets orthroats of each group of horns, for example of alternate horns in eachof'the rows are acoustically coupled. For example, the inlets ofalternate horns may merge into a common sound duct or extend into acoupler mem-- 0 her to which one of the receivers is coupled.

' In accordance with another feature of'thisin- L vention, the severalhorns are so designed that a smooth transition is obtained between the.in-

let of the coupler member and the throats of the horns associatedtherewith. For. example,

the horns may have rectangular .mouths and the coupler member may have acircular inlet and may flare to a substantially square outlet.

The horns are then flared so that they termi nate in substantiallysquare inlets, the square form preferably obtaining onlyimmediatelyadjacent the inlets.

The invention and the foregoing and other features thereof will beunderstood more clearly and fully from the followingdetailed'description with reference-to the accompanying drawings inwhich'z, a Fig. l isa perspective view of a loud-speaker including atransducer constructed in accordance 0 with this invention;

Figs. 2 and 3 are front and "side views, respectively, of the transducershown in Fig. 1; and

' Fig. 4 is an end view of a coupler member for connecting the inlets orthroats of alternate horns 5 of the transducer.

The horns l0 .to2l preferably are 'of substan- Referring now to thedrawings, the'device therein shown comprises a plurality of horns ID to2| .inclusive, disposed adiacent one another and arranged in threerows-of'four horns each.

tially the same length and flare continuously from their inlets to theirmouths or outlets, preferably so that the cross-sectional area of eachof the passageways increases exponentially to,- ward and to the mouth oroutlet. The passage- 10 ways in the horns are substantially identicaland may be square in section at the inlet end and rectangular in sectionat all other points. Preferably the outlets or mouths of the severalhorns are disposed in a plane, adjacent edg'esof the mouths beingsubstantially coincident as shown clearly in Fig. 2, and suitablysecured together, for example by welding.

The outermost of the horns may be suitably secured, as by welding, to. arigid rectangular 2 frame 22 having afllxed thereto suitable rings a oreyelets 23 by means of which the loud-speak er may be supported. Asshown clearly in Figs. land 3, alternate horns in each of the horizontalrows and corre- '2 sponding horns in the vertical rows are acoustically'connected at their inlets or throats,'as, for example, by couplermembers 24. More specifically, referring particularly to Fig. 2, all ofthe even numbered horns are connected at their throats to one of thecoupler members 24 and all of'the odd numbered horns are similarlyconnected to the other of the coupler members 24.-

Metalllc bands 30 may be provided to hold the I throat portions of thehorns of a group to- 35 gether. I

Aswill be seen from Fig. 4, thecoupler members 24 have circular inlets26 and flare, preferably exponentially, to square outlets 21 in whichthe inlets or throats of the horns are fitted. 4o

Each of the coupler members hasconnected thereto a suitable receiver 25,which may be, for example, of the design disclosed in Patent 2,037,- 187granted April, l4, 1936 to Edward C. Wente.

As a result of the flare and change in section of; 45

the passageways in each of the coupler memj bers a smooth transitionresults between the outlets of the receivers 25 and the inlets orthroats of the horns whereby distortion of the sound output of thereceivers is prevented. 50.

Becauseof the association of the various horns with the receivers asabove described, the com; bined sound outputof the two receivers will bedistributed uniformly throughout a large-space angle so that uniformquality and intensity of speech and music will obtain throughout thesound field of the loud-speaker. This uniformity will obtain, it will beseen, even though one of the receivers should become inoperative.

Although in the specific embodiment shown in the drawings correspondingor vertically aligned horns are coupled to and receive energy from acommon receiver, the various horns maybe connected in other manners. Forexample, horns II, it, I, H, il and 2| may have their inlets or throatsconnected to one coupler member and the remaining horns may have theirinlets or throats connected to another coupler member.

The various horns I I to It may be fabricated of sheet metal and mayhave the outer surfaces thereof covered with a vibration dampingmaterial. For example, sheets of mating p pe may be cemented to thewalls of the horns .to prevent 'vibration thereof. Also, if desired, thespaces betweenthewaiisofthehorns maybefilied with a sound absorbingmaterial, such, forexample, as felt or cotton waste, to eliminate ton oivibrations between the horns.

Although a specific embodiment ot the invention has been shown anddescribed, it will be understood, of course, that various modificationsmay be made therein without departing from the scope and spirit of thisinvention as defined in the appended claims What is claimed .is:-

plicity of horns disposed. adjacent one .another and each having aninlet and an outlet, and: means acoustically coupling the inlets of onlyalternate horns.

2. An acoustic transducer comprising a plurality of horns having inletsand outlets and I eachhaving therein a sound passageway flaring from theinlet to the outlet, the passageways in said horns being of the sameconfiguration and of substantially the same length, the outlets of saidhorns being adjacent one another, and means acoustically connecting onlythe ,inlets corresponding to alternate of said outlets.

8. An acoustic device comprising a multiplicity of horns each having 'aninlet and an outlet, the

ternate outlets in said rows.

of horns disposed in a plurality of equal rows and having their mouthslaterally adjacent one another, means acoustically coupling only the 1.An acoustic transducer comprising a muiti connecting only --the inlets.corresponding'to al- 5. An acoustic device comprising a plurality 7. Anacoustic device comprising a pair of receivers, a pair of couplermembers'each connected to one of said receivers, a group of horns havingtheir throats connected to one of said coupler members, and a secondgroup of horns having their throats connected to the other of saidcoupler members, said horns having their mouths disposed adjacent oneanother and the mouths of the horns of one group being alternatelyarranged with the mouths of the horns of the other group.

-8. An acoustic device comprising a group'of horns arranged with theirmouths in a plurality mouths in rows, andv means acoustically separatefrom said first means coupling the throats of said second horns, atleast one row of mouths of the horns in each group being' disposedbetween two 'ws of mouths-oi the horns in the other group.

. of rows, means couplingthe throats of said horns, a second group ofhorns arranged with their 9. An acoustic device in accordance with claim8 wherein the mouths of all of the horns are disposed in a plane.

10. An .acousticdevice comprising a pair of coupler members havingsquare outlets, a pair of receivers each connected to the inlet of oneof said coupler members, and a transducer comprising a plurality ofhorns havingmectangular mouths and square throats, said horns beingdisposed in a plurality of equal rows, one group of correspondingalternate horns in said rows having their throats. connected to theoutlet of one of'said coupler'members, and the remainder of said hornshaving their throats connected to the other of said coupler members.

1l.-' Sound reproducing apparatus comprising a plurality of groups ofhorns, portions of the horns of one group being interleaved withportions of the horns of another group, means acoustically coupling theinlets 'of only the horns in each of said groups, and a plurality ofreceivers each associated only with the horns of one of said groups.

12. An acoustic transducer comprising a plurality of groups of horns,each .group comprising a plurality of horns, the horns of each grouphaving a common inlet, the inlet of each group being acousticallyseparate from each other group, and the outlets oi. a portion of thehorns of one group being interleaved with the outlets of a portion ofthe horns of another group.

I mnnaiucx a MARION.

